To identify human bone marrow stromal cell(BMSC) subsets with enhanced ability to engraft/contribute to the resident intestinal cellular pool, we transplanted clonally derived BMSCs into fetalsheep. Analysis at 75 d posttransplantation showed 2 of the 6 clones engrafting the intestine at 4 to 5fold higher levels (5.03±0.089 and 5.04±0.15%, respectively) than the other clones (P<0.01), correlating with the percentage of donorderived Musashi1 (12.01–14.17 vs. 1.2–3.8%; P<0.01) or leucinerich repeatcontaining Gprotein coupled receptor 5 (Lgr5) cells within the intestinalstem cell(ISC) region. Phenotypic and transcriptome analysis determined that the clones with enhanced intestinal contribution expressed high levels of Ephrin type B receptor 2 (EphB2). Intestinal explants demonstrated proliferation of the engrafted cells and ability to generate cryptlike structures in vitro still expressing EphB2. Additional transplants based on BMSC EphB2 expression demonstrated that, at 7 d posttransplant, the EphB2 BMSCs engrafted in the ISC region at levels of 2.1 ± 0.2%, while control EphB2 BMSCs engrafted at 0.3 ± 0.1% (P<0.01). Therefore we identified a marker for isolating and culturing an expandable subpopulation of BMSCs with enhanced intestinal homing and contribution to the ISC region.— Colletti, E., El Shabrawy, D., Soland, M., Yamagami, T., Mokhtari, S., Osborne, C., Schlauch, K., Zanjani, E. D., Porada, C. D., AlmeidaPorada, G. EphB2 isolates a human marrow stromal cellsubpopulation with enhanced ability to contribute to the resident intestinal cellular pool